Mechanical movement



April 10, 1962 K. s-ru'rz 3,028,762

MECHANICAL 'MOVEMENT Filed Jan. 1s, 1959 3,028,762 MECHANICAL MOVEMENT Karl Stutz, Hinterbramberg 6, Lucerne, Switzerland Filed Jan. 13, 1959, Ser. No. 786,522 t Claims priority, application Switzerland Jan. 15, 1958 1 Claim. (Cl. 7489) This invention is concerned with an improved mechanical movement for moving an actuating member between an inoperative position and an effective position, and is applicable particularly, though not exclusively, to means for retracting the lock-release cam of a lift cage.

The cam of a lift cage usually assumes the form of a projecting rail mounted upon the cage and adapted, when the latter reaches any given floor level, to engage a roller-carrying lever through the medium of which the lock of the associated shaft door or gate is automatically released.

ln this connection it has become customary to hold the release cam retracted and to allow it to resume an ellective position only when the cage reaches the intended stopping place, so that the shaft doors or gates at intermediate stopping places are not ailected and remain locked as the cage passes by.

An object of the present invention is to provide a simple, reliable and robust mechanical movement for operating a control member such as the lock-'release cam aforesaid.

According to the invention, the mechanical movement for alternately iuactivating and rendering ellective a control member, such as the lock-release cam of a lift cage, comprises an actuating member operatively connected to a follower roller which engages with the helical peripheral face of a rotary cam having two spaced abutment portions and rotatable by an electric motor so that outward movement of the roller with reference to the cam axis moves the actuatingr member to an inoperative position in which the follower roller engages that abutment portion which is more distant from the cam axis. The mechanical movement further comprises resilient means adapted, upon switching-off of the motor, to cause reverse rotation of the cam until the actuating means assumes an operative position in which the follower roiler abuts against the other abutment portion.

The accompanying drawing shows diagrammatically one embodiment of the invention as applied to the lockrelease mechanism of a lift cage.

Mounted in or on the lift cage is an electric motor (not shown), preferably of squirrel-cage type, whose shaft 1 has keyed thereto a disc shaped cam 2 with a peripheral face 3 terminating in abutment portions or stops 4 and 5 with arcuate concavities.

The peripheral face 3 is of helical form (that is to say, its effective radius increases uniformly from the stop 4 to the stop 5) and is at all times engaged by a follower roller 6 at the free end of an arm 7 pivoted at 9 to the motor casing, the roller 6 normally abutting the inner stop 4 so that rotation of the cam 2 in the direction of the arrow P has the effect of raising the arm 7. Preferably this roller 6 has a semi-plastic covering.

The free end of the arm 7 or preferably the spindle of the roller 6, is linked by an elongated motion trans- "ice mitting member or link 10 to the actuating member or lever 13 associated with a conventional lock-release cam (not shown), a resilient element in the form of a spring 8 connected to the lever 13 biassing the lock-release cam to its elective position, in which the lock-release cam is adapted to actuate in known manner the lock-release lever (not shown) of a shaft door or gate.

In the event of the lift cage being set in motion by appropriate operation of internal or external control means, the electric motor is energized to rotate the cam 2 until the outer stop 5 thereon engages the roller 9, the resultant lifting of the lever 13 through the medium of the link 10 causing a retraction of the lock-release cam. The spring-loaded lock-release lever will simultaneously move outwards to permit automatic locking of the shaft door or gate at the oor-level from which the lift cage is starting, and due to the inoperative position of the lock-release cam any other doors or gates which the cage may pass on its journey will remain locked.

When the cage reaches its destination level, however, the electric motor is automatically switched oil and the pull of the spring-loaded link 10 upon the arm 7 causes the cam 2 to rotate backwards until the stop ft once more abuts the roller `6, the lift-release thereupon resuming its effective position so that the adjacent shaft door or gate can be opened.

What I claim is:

A mechanical movement comprising, in combination, a cam having an axis of rotation and formed with a helical peripheral face having two spaced oppositely directed abutment portions, one of said .abutment portions more distant from said axis than the other abutment portion; means including a shaft for rotating said cam about said axis in a rst direction; a follower roller having an axis of rotation parallel with said rst mentioned axis and engaging with said face;` an elongated motion transmitting member having a rst end secured to said roller and a second end; an actuating member having an end pivotable about a fixed axis and articulately connected with the second end of said motion transmitting member; and resilient means connected with said actuating member for permanently biasing said motion transmitting member in a direction to maintain said roller in engagement with the face of said cam, said mechanical movement operating in such `a way that, when the cam is rotated in said rst direction to move said one abutment portion into engagement with said roller, said resilient means automatically rotates the cam in a second direction counter to said rst direction until said roller engages with the other abutment portion.

References Cited in the lile of this patent UNITED STATES PATENTS 382,101 McKnight May 1, 1888 720,322 Burkholder Feb. 10, 1903 A2,556,304 Velkas et al. lune 12, 1951 2,630,738 Borberg Mar. 10, 1953 2,778,232 Mork Jan. 22, 1957 FOREIGN PATENTS 294,496 Great Britain July 24, 1928 

